Correct way of holding the stick during ground roll?

At 23:51 04 May 2009, Eric Greenwell wrote:
Steve Leonard wrote:
My suggestioin would be stick forward to get the tail in the air.
This
way, you are in control of the airplane. If you leave the tail in the
ground, the airplane will take off when it wants to, leaving you to
react
to what it has just done. I believe your task is to make the airplane
do
what you want it to do, and not to try to catch up with what it just
did.

Steve's method is the commonly used one on a good runway surface (and a

cross wind is not a significant factor), as it's easier to control the
glider; however, keeping the tail on the ground is a standard method for

soft field takeoffs, when you want the main wheel weight reduced as fast

as possible. It may also be useful on a rough field, when you want to
get off the ground as soon as possible. It is the recommended method for

both situations in my ASH 26 E flight manual.

It is very common in flapped gliders to nail the tailwheel to the ground
and you are able to do this because with full negative flap you are not
going to leave the ground or "winch launch" behind the tug. Keeping the
tailwheel on the ground is definitely the thing to do in a crosswind. In
many, if not all flapped gliders with full negative flap the tug may get
airborn but the glider is going by road. However for gliders which do not
have a flaps, or if they do, do not have a negative setting great care is
needed and keeping the tailwheel firmly on the ground for too long can
result in something very scary.

On May 4, 3:12*am, Michael wrote:
Very beginning pilot here (again).....and I am confused about the
appropriate way of holding the stick during the ground roll prior to
take off.

In Thomas Knauff's Glider Basics, he states (p.59, 2005 edition):
"....before signaling to proceed with the launch, the glider pilot
should set the elevator by holding the control stick at the
approximate position that will result in the proper angle of attack.
To do this, move the control stick the full allowable travel fore and
aft, and then find the mid-point, or neutral position. *Move the
control stick back about 1/2 inch from this neutral position. *This
will be very close to the optimum position for takeoff. Aircraft
designers build aircraft this way."

However, in Russell Holtz's Flight Training for Gliders, I see (p. 27,
2008 edition): "If the glider norally rests on its main wheel and tail
wheel, the stick should be held forward of neutral, so the as the
glider picks up speed, the tail wheel will rise off the ground."

I'm training in a Blanik L-23, which has a main wheel and a
tailwheel. * Knauff makes no mention of whether to hold the stick
forward or aft depending on if the glider has a tail wheel or a nose
wheel, yet Holtz does.

(It's been three weeks since I've flown, and I can't remember what my
instructors did.)

For a glider with a tail wheel, which is correct?

--Michael

Careful !

It depends on the glider, launch mechanism, and weather.

Tom's advice is the best general advice you'll find.

For a glider with a non-swiveling tailwheel or tailskid,
in a cross-wind, proper procedure MAY be full
back, to keep the glider tracking straight until
you have good directional control.

There are plenty of gliders where lifting the tail
too soon with even a mild crosswind will cause
an immediate turn into the wind...

Talk to your instructor !
And review the proper procedure
when flying a new type...

Hope that helps,
See ya, Dave "YO electric"

PS: Tom's advice worked for the first-time 1-26
student pilot I briefed yesterday - absolutely no PIO...

Dave Nadler wrote:
Careful !

It depends on the glider, launch mechanism, and weather.


"It depends" is good advice from Dave. to further illustrate the point,
in a nose dragger, you'd be generally advised to hold the stick back
to get the skid / nose wheel off the ground ASAP. However, if this nose
dragger happens to a 2-33 and the tow plane makes an abrupt start, the
skid will come off the ground by itself and the tail will slam onto the
ground and there's nothing that you can do about it. You'd be well
advised to start with the stick full forward in this case.

On a calm wind day, The starting position of the stick is not too
important, IMHO, because the controls are relatively ineffective at the
start. When the wind blows, it's another story.

Tony V.

On May 4, 6:42*am, TonyV wrote:
Dave Nadler wrote:
Careful !

It depends on the glider, launch mechanism, and weather.

"It depends" is good advice from Dave. to further illustrate the point,
* in a nose dragger, you'd be generally advised to hold the stick back
to get the skid / nose wheel off the ground ASAP. However, if this nose
dragger happens to a 2-33 and the tow plane makes an abrupt start, the
skid will come off the ground by itself and the tail will slam onto the
ground and there's nothing that you can do about it. You'd be well
advised to start with the stick full forward in this case.

On a calm wind day, The starting position of the stick is not too
important, IMHO, because the controls are relatively ineffective at the
start. When the wind blows, it's another story.

Tony V.

Not to be overly facetious, but if you are positioning the primary
controls based on directions you took off the Internet, you are likely
to end up a bit behind the glider.

One of the main ideas in flight training is to develop a strong sense
of what you want the airplane to do under any circumstance and how you
need to manipulate the controls to get the airplane to do exactly
that. A mechanistic approach to flying will inevitably get you into
trouble. This, of course, is why when you ask what seems to be a
simple, mechanical question you get a dozen (or more!) replies with a
lot of "it depends" included.

Having said that, I know it isn't super helpful to someone with less
than a handful of lessons. I think you've gotten a sense from the
replies that there are many differences that determine the right
answer. Differences in: glider configuration (tailwheel - swiveling
or fixed versus nosewheel/skid AND cockpit loading/cg), wind
conditions (stong/weak, head/cross), tow type and profile (aero/winch,
fast/slow acceleration), wing runner performance (pointed down the
runway with wings level vs all sorts of messed up attitudes). What you
need to do in one circumstance can be totally different for another.

THAT said, generally with a glider with a fixed tailwheel that tends
to sit on the tail with the pilots aboard, reasonable wind conditions,
a straight and true wing run and an aero tow behind a towplane with
average power for the density altitude (forgot to put that one on my
list), your first instinct should be to push the stick modestly
forward once you have a little airspeed to get the tailwheel off the
ground so you can steer with the rudder and to put the wing at a
normal flying angle of attack so that the glider doesn't balloon off
the runway once it gets flying speed.

Again - you are the pilot. You will need to understand the balance of
all the forces on the glider and how moving the controls will change
that in ways that are predictable.

9B

At 17:58 04 May 2009, wrote:
On May 4, 6:42=A0am, TonyV wrote:
Dave Nadler wrote:
Careful !

It depends on the glider, launch mechanism, and weather.

"It depends" is good advice from Dave. to further illustrate the
point,
=A0 in a nose dragger, you'd be generally advised to hold the stick
back
to get the skid / nose wheel off the ground ASAP. However, if this
nose
dragger happens to a 2-33 and the tow plane makes an abrupt start, the
skid will come off the ground by itself and the tail will slam onto
the
ground and there's nothing that you can do about it. You'd be well
advised to start with the stick full forward in this case.

On a calm wind day, The starting position of the stick is not too
important, IMHO, because the controls are relatively ineffective at
the
start. When the wind blows, it's another story.

Tony V.

Not to be overly facetious, but if you are positioning the primary
controls based on directions you took off the Internet, you are likely
to end up a bit behind the glider.

One of the main ideas in flight training is to develop a strong sense
of what you want the airplane to do under any circumstance and how you
need to manipulate the controls to get the airplane to do exactly
that. A mechanistic approach to flying will inevitably get you into
trouble. This, of course, is why when you ask what seems to be a
simple, mechanical question you get a dozen (or more!) replies with a
lot of "it depends" included.

Having said that, I know it isn't super helpful to someone with less
than a handful of lessons. I think you've gotten a sense from the
replies that there are many differences that determine the right
answer. Differences in: glider configuration (tailwheel - swiveling
or fixed versus nosewheel/skid AND cockpit loading/cg), wind
conditions (stong/weak, head/cross), tow type and profile (aero/winch,
fast/slow acceleration), wing runner performance (pointed down the
runway with wings level vs all sorts of messed up attitudes). What you
need to do in one circumstance can be totally different for another.

THAT said, generally with a glider with a fixed tailwheel that tends
to sit on the tail with the pilots aboard, reasonable wind conditions,
a straight and true wing run and an aero tow behind a towplane with
average power for the density altitude (forgot to put that one on my
list), your first instinct should be to push the stick modestly
forward once you have a little airspeed to get the tailwheel off the
ground so you can steer with the rudder and to put the wing at a
normal flying angle of attack so that the glider doesn't balloon off
the runway once it gets flying speed.

Again - you are the pilot. You will need to understand the balance of
all the forces on the glider and how moving the controls will change
that in ways that are predictable.

9B
When flying a 2-33 or 2-22, which have high wings supported by struts and
which normally rest on their nose skids because the main wheel is aft of
the CG, rapid acceleration and light cabin load will allow the nose to
rapidly rise and the tail to bang in a way that is good niether for the
airframe nor the psyche. Furthermore, you will expose a lot of wing to the
propwash of the towplane, and in the case of a Pawnee, that can be
substantial. With your nose high and strong propwash, you will get a rapid
and sometimes nearly uncontrollable roll movement to the right. It will
come into control within a moment or two, but those two moments are
exciting, even for veteran 2-33ers. Lesson: pay attention to loading and
if you think you are lighter than average, ask the tow pilot to go easy on
the throttle in the start of the roll.

When flying a 2-33 or 2-22, which have high wings supported by struts and
which normally rest on their nose skids because the main wheel is aft of
the CG, rapid acceleration and light cabin load will allow the nose to
rapidly rise and the tail to bang in a way that is good niether for the
airframe nor the psyche. Furthermore, you will expose a lot of wing to the
propwash of the towplane, and in the case of a Pawnee, that can be
substantial. With your nose high and strong propwash, you will get a rapid
and sometimes nearly uncontrollable roll movement to the right. It will
come into control within a moment or two, but those two moments are
exciting, even for veteran 2-33ers. Lesson: pay attention to loading and
if you think you are lighter than average, ask the tow pilot to go easy on
the throttle in the start of the roll.


Then you need to tell your tow pilot to be a little more gentle with
throttle application.
Even with light students in the front seat, smoother application of the tow
throttle can keep the nose from rocketing up while still providing enough
acceleration to provide roll and pitch control.

BT

On May 4, 3:12*am, Michael wrote:
Very beginning pilot here (again).....and I am confused about the
appropriate way of holding the stick during the ground roll prior to
take off.

In Thomas Knauff's Glider Basics, he states (p.59, 2005 edition):
"....before signaling to proceed with the launch, the glider pilot
should set the elevator by holding the control stick at the
approximate position that will result in the proper angle of attack.
To do this, move the control stick the full allowable travel fore and
aft, and then find the mid-point, or neutral position. *Move the
control stick back about 1/2 inch from this neutral position. *This
will be very close to the optimum position for takeoff. Aircraft
designers build aircraft this way."

However, in Russell Holtz's Flight Training for Gliders, I see (p. 27,
2008 edition): "If the glider norally rests on its main wheel and tail
wheel, the stick should be held forward of neutral, so the as the
glider picks up speed, the tail wheel will rise off the ground."

I'm training in a Blanik L-23, which has a main wheel and a
tailwheel. * Knauff makes no mention of whether to hold the stick
forward or aft depending on if the glider has a tail wheel or a nose
wheel, yet Holtz does.

(It's been three weeks since I've flown, and I can't remember what my
instructors did.)

For a glider with a tail wheel, which is correct?

--Michael

Michael,

Get a copy of the Condor soaring simulator (www.condorsoaring.com) and
do a 100 or so takeoffs in various wind conditions and different
sailplanes. Condor is realistic enough so you will get the picture
(literally) quickly.

What others may not have mentioned explicitly is that the initial
period only lasts for a few seconds during the first part of the
ground run. Once you have enough airspeed for decent elevator control,
then the initial stick position is irrelevant - you do whatever is
required to obtain the correct flying attitude during the rest of the
ground roll and takeoff.

Just my $0.02.
Frank (TA)

On May 4, 12:12*am, Michael wrote:
Very beginning pilot here (again).....and I am confused about the
appropriate way of holding the stick during the ground roll prior to
take off.

In Thomas Knauff's Glider Basics, he states (p.59, 2005 edition):
"....before signaling to proceed with the launch, the glider pilot
should set the elevator by holding the control stick at the
approximate position that will result in the proper angle of attack.
To do this, move the control stick the full allowable travel fore and
aft, and then find the mid-point, or neutral position. *Move the
control stick back about 1/2 inch from this neutral position. *This
will be very close to the optimum position for takeoff. Aircraft
designers build aircraft this way."

However, in Russell Holtz's Flight Training for Gliders, I see (p. 27,
2008 edition): "If the glider norally rests on its main wheel and tail
wheel, the stick should be held forward of neutral, so the as the
glider picks up speed, the tail wheel will rise off the ground."

I'm training in a Blanik L-23, which has a main wheel and a
tailwheel. * Knauff makes no mention of whether to hold the stick
forward or aft depending on if the glider has a tail wheel or a nose
wheel, yet Holtz does.

(It's been three weeks since I've flown, and I can't remember what my
instructors did.)

For a glider with a tail wheel, which is correct?

--Michael

Michael,

I wanted to respond to your questions with the reasons that I advocate
the takeoff technique described in the Flight Training Manual for
Gliders.

I recommend getting the glider balanced on the main wheel as soon as
possible. You can see why this is important if you look at what can
happen if you keep either the tail wheel or the nose wheel on the
ground too long.

In a tail dragger, if you hold too much back pressure (or the elevator
is trimmed too far back) the glider will lift off while the tail is
still being “pushed” into the ground by the elevator. The glider can
then lift it’s main wheel off of the ground, but keep increasing it’s
angle of attack because the excess back pressure keeps the tail wheel
on the ground. The glider can either stall, or more likely, lurch
into the air and climb rapidly. This could pull the tail of the tow
plane up, driving it’s nose into the ground. Or, as the glider lifts
off rapidly, the pilot/student will often over control, causing the
glider to slam back down to the ground, possibly starting a pilot
induced oscillation.

With a nose dragger, if you hold too much forward pressure (or the
elevator is trimmed too far forward), the glider can reach flying
speed, yet still not be flying because the angle of attack is too low
to generate sufficient lift. If the stick is then moved back to lift
the nose, the glider can lurch into the air quickly, causing the same
problems just described.

And finally, look what could happen if the glider hits a bump while
rolling on the nose or tail wheels, as opposed to what happens if it
hits a bump while balanced on the main wheel. A bump to the tail
wheel can damage it, or drive the nose into the ground. A bump to the
nose wheel can cause a rapid increase in angle of attack which, if
sufficient speed has been reached, can cause the glider to lurch into
the air, or if flying speed has not been reached, the glider can slam
onto the tail wheel, damaging it or the rear fuselage. If you hit a
bump while balancing on the main wheel, the force will act very near
the center of gravity, and will not cause a change to the pitch or
angle of attack.

So, whether you are flying a tail dragger or a nose dragger, the goal
should be to get the glider in to a flying attitude as soon as
possible. To achieve this, during the initial roll on take off, make
sure the stick is held well forward in a tail dragger, or well aft in
a nose dragger.

I hope this helps to clear things up.

Russell Holtz

In message
,
writes
snip

So, whether you are flying a tail dragger or a nose dragger, the goal
should be to get the glider in to a flying attitude as soon as
possible. To achieve this, during the initial roll on take off, make
sure the stick is held well forward in a tail dragger, or well aft in
a nose dragger.

This is not the advice I was trained to in the UK. For an aerotow we
always start with the stick right back, and easy it forwards as the tug
accelerates. This we do with both taildraggers (the average
single-seater) and gliders like the K21 and DG500/505 that rest on the
nose wheel once the crew is in. The runway is usually grass.

For a winch launch we start with a neutral stick as acceleration to
flying is usually very fast, and it's vital that the early part of the
flight and the rotation are well-controlled.

Ask your instructor to run through it again next time you fly - IMHO
that's much safer than taking advice from anonymous strangers and
possibly finding it's not what your instructor wants you doing.

--
Surfer!
Email to: ramwater at uk2 dot net

At 07:11 06 May 2009, Surfer! wrote:
In message
,
writes


So, whether you are flying a tail dragger or a nose dragger, the goal
should be to get the glider in to a flying attitude as soon as
possible. To achieve this, during the initial roll on take off, make
sure the stick is held well forward in a tail dragger, or well aft in
a nose dragger.

This is not the advice I was trained to in the UK. For an aerotow we
always start with the stick right back, and easy it forwards as the tug
accelerates. This we do with both taildraggers (the average
single-seater) and gliders like the K21 and DG500/505 that rest on the
nose wheel once the crew is in. The runway is usually grass.

For a winch launch we start with a neutral stick as acceleration to
flying is usually very fast, and it's vital that the early part of the
flight and the rotation are well-controlled.

Ask your instructor to run through it again next time you fly - IMHO
that's much safer than taking advice from anonymous strangers and
possibly finding it's not what your instructor wants you doing.

--
Surfer!
Email to: ramwater at uk2 dot net



Just out of interest, what is the reason given for holding the stick back
and gradually easing forwards for all gliders? i can understand for a
'nose dragger' (for want of a better term) especially on grass to avoid
damage to the nose wheel. I would always be inclined to adopt the
technique as described in the previous posting.

matt